The Embedded Firmware DSA Interview Guide: 248 Questions and Answers
248 data structures and algorithms interview questions answered for embedded and firmware engineers, across seven parts covering C, arrays, lists, trees and more.
FreeRTOS Semaphore vs Mutex on STM32: Ownership, Priority Inheritance, and Why They Are Not Interchangeable
Most FreeRTOS synchronisation tutorials treat semaphores and mutexes as two flavours of the same thing — a binary flag you acquire and release. That framing
FreeRTOS Queues on STM32: Copy Semantics, the ISR Boundary, and the Anti-Patterns That Cause Silent Data Loss
Most FreeRTOS queue tutorials stop at xQueueSend and xQueueReceive — the two calls that were never the hard part. They show you a producer task,
Event-Driven Firmware Architecture
Most write-ups on event-driven firmware stop at the conceptual layer: events decouple modules, a queue holds them, a dispatcher routes them. That part is easy
Secure Boot and OTA Firmware Updates on ARM Cortex-M: A Production Guide to TrustZone, MCUboot, and Rollback Protection
For the architecture decisions behind this guide (root of trust, key hierarchy and rotation, anti-rollback storage and debug lock), see Firmware Security Architecture, part 8
Hierarchical State Machines (HSM) in C for Telecom and RF Firmware
In telecom, RF, SATCOM, and industrial communication products, firmware coordinates dozens of subsystems that all run at once: PLL lock supervision, thermal protection, VSWR monitoring,
STM32 + ESP32/ESP8266 MQTT Tutorial with FreeRTOS: Build Production-Grade IoT Systems (2026 Guide)
Build production-grade IoT firmware using STM32, FreeRTOS, and MQTT with ESP32 as a Wi-Fi coprocessor. Covers task isolation, queue-driven design, UART DMA, reconnection state machines, security, and real production deployment patterns.
STM32 Low Power Modes Explained: Sleep, Stop & Standby for Battery-Powered IoT Devices
Learn how STM32 Sleep, Stop, and Standby modes work — with real HAL code, RTC wakeup design, FreeRTOS Tickless Idle, GPIO leakage fixes, and battery life estimation techniques for professional IoT firmware engineers.
Getting Started with Zephyr RTOS on STM32 — Complete Beginner to Professional Guide (2026)
Learn how to get started with Zephyr RTOS on STM32 in this complete 2026 guide — covering setup, Device Tree, Kconfig, BLE development, OTA with MCUboot, power management, and why Zephyr is the most important RTOS skill for embedded engineers today.
ISR Integration — ISR-safe APIs, the syscall-priority boundary, and deferred interrupt processing
Previously: Semaphore vs Mutex | Next: Heap Management Why ISRs Are Different — The One Rule You Cannot Break An Interrupt Service Routine runs outside
